The week has been dry and sunny but with the clouds progressively becoming a more frequent feature. Increasingly the skies are becoming overcast and the azure blue of the dry season has been replaced by a blanket of grey. The sun manages to peep through for a while but then is lost once more behind an obscuring haze, only the faint outline of its orange disc visible to the naked eye.

The amphibian population is gathered and ready for the real rains to begin. There are more male frogs setting up territories at each location around the pond. The Savage’s Thin-fingered frog and the Marine Toads prefer the pond edge. The Banana Frogs and the Small-headed Frogs situate themselves on the vegetation floating on the water. A little higher up the Milky Frogs have taken up their positions on the upper surfaces of the leaves overhanging the water. Finally the Red-eyed Green Tree Frogs can be heard calling from nearer the tops of the vegetation. When the rains do arrive, with the typical early May deluges, the activity around the pond will increase exponentially. More species will arrive, particularly the ones that reproduce directly in the water. It is just a matter of time.

Red-eyed Green Tree Frog, (Agalychnis callidryas). Male. Calling.

Skipping Over Marked Metal

Butterflies exhibit a variety of dimorphisms. They may be sexually dimorphic, strongly or otherwise, males and females may look like completely different species. They maybe seasonally dimorphic, wet season forms differing from dry season forms. They may be geographically polymorphic with one species varying in size, color and markings over a wide geographical range to the point where you would once again think you were looking at totally different species.

One of the more commonly seen riodinids, or metalmark butterflies, in the forests of Bosque del Cabo is Metacharis victrix. I regularly see the fiery orange females but not so often the males which are much more of a deep brick red. They have the frustrating habit of perching on the underside of leaves so to capture the image you have to get on the ground, lie on your back and point the camera upwards.

Metacharis victrix. Male.

They are frequently found in bright understory light gaps. The larval food plant is any one of the Heisteria species of which, Heisteria accuminata, is very abundant in this area.

Heisteria accuminata. Fruit

The skippers are a difficult family of butterflies to identify too. A great many of them are very small, sometimes no bigger than an adult human fingernail. To add to the problem of identity, there are so many of them and they quite often they are muted shades of brown. It does take a certain level of expertise to identify them to species level.

Last week I had one land close to me and fortunately stay still. Skippers are prone to taking flight at the slightest disturbance and are also averse to the camera flash going off. This individual was the Perching Saliana (Saliana esperi). The earthy brown of the hindwing underside has a contrasting creamy flash. There are two pale windows in the dark half of the wing.

Perching Saliana, (Saliana esperi)

It’s a Mystery

As much as I would love to study moths as well as butterflies, time does not allow this luxury. There are up 14,000 species of butterfly and moth in Costa Rica, the majority being moths. Many of the moths we have no idea of their life histories. So when a moth does turn up that I can take a photograph of, if I cannot arrive at an identity then I do not fret over the fact, I just enjoy it for what it is, a beautiful thing to behold.

Unidentified Moth

Actually that holds true for many insects. Costa Rica has an estimated 365,000 named species of insects within its territory, that is 1,000 species for every day of the year, which would require exceptional identification skills. Identity to species level is best left in the hands of those who specialize in a particular group. I found a stinkbug sitting on a leaf that made a wonderful subject but I have not been able to name it to species level.

Unidentified Stinkbug

Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica